In recent years, in order to achieve high breakdown voltage and low loss of semiconductor devices, use thereof in a high temperature environment, and the like, silicon carbide has begun to be adopted as a material for semiconductor devices. Silicon carbide is a wide band gap semiconductor having a band gap larger than that of silicon, which has been conventionally widely used as a material for semiconductor devices. Hence, by adopting silicon carbide as a material for a semiconductor device, the semiconductor device can have a high breakdown voltage, reduced on-resistance, and the like. Further, the semiconductor device adopting silicon carbide as its material also has an advantage that its characteristics are less likely to be deteriorated when it is used in the high temperature environment, when compared with a semiconductor device adopting silicon as its material.
For example, Japanese Patent Laying-Open No. 2011-82546 (PTD 1) describes a method for dividing a wafer made of a gallium nitride-based compound semiconductor or the like. According to the method for dividing the compound semiconductor wafer, first, a groove portion is formed in a compound semiconductor layer in a separation zone, and thereafter a division groove is formed by a laser method. Next, the compound semiconductor wafer is immersed in a chemical solution of an acid such as phosphoric acid, nitric acid, or hydrochloric acid, and thereby contamination on the periphery of the division groove is removed by wet etching.